[Federal Register Volume 69, Number 183 (Wednesday, September 22, 2004)]
[Rules and Regulations]
[Pages 56711-56718]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-20982]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-2004-0278; FRL-7679-5]


Tribenuron Methyl; Pesticide Tolerance

AGENCY: Environmental Protection Agency EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes a tolerance for residues of 
tribenuron methyl in or on canola, seed; cotton, gin byproducts; 
cotton, undelinted seed; and flax, seed. E.I. DuPont De Nemours and 
Company requested this tolerance under the Federal Food, Drug, and 
Cosmetic Act (FFDCA), as amended by the Food Quality Protection Act of 
1996 (FQPA). In addition, this regulatory action is part of the 
tolerance reassessment requirements of section 408(q) of the FFDCA 21 
U.S.C. 346a(q), as amended by the FQPA of 1996. By law, EPA is required 
to reassess 100% of the tolerances in existence on August 2, 1996, by 
August 2006. This regulatory action will count for eight reassessments 
toward the August 2006 deadline.

DATES: This regulation is effective September 22, 2004. Objections and 
requests for hearings must be received on or before November 22, 2004.

ADDRESSES: To submit a written objection or hearing request follow the 
detailed instructions as provided in Unit VI. of the SUPPLEMENTARY 
INFORMATION. EPA has established a docket for this action under Docket 
identification (ID) number OPP-2004-0278. All documents in the docket 
are listed in the EDOCKET index at http://www.epa.gov/edocket. Although 
listed in the index, some information is not publicly available, i.e., 
CBI or other information whose disclosure is restricted by statute. 
Certain other material, such as copyrighted material, is not placed on 
the Internet and will be publicly available only in hard copy form. 
Publicly available docket materials are available either electronically 
in EDOCKET or in hard copy at the Public Information and Records 
Integrity Branch (PIRIB), Rm. 119, Crystal Mall 2, 1801 S. 
Bell St., Arlington, VA. This docket facility is open from 8:30 a.m. to 
4 p.m., Monday through Friday, excluding legal holidays. The docket 
telephone number is (703) 305-5805.

FOR FURTHER INFORMATION CONTACT: James Tompkins, Registration Division 
(7505C), Office of Pesticide Programs, Environmental Protection Agency, 
1200 Pennsylvania Ave., NW.,Washington, DC 20460-0001; telephone 
number: 703-305-5697 e-mail address: [email protected].

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does This Action Apply to Me?

    You may be potentially affected by this action if you are an 
agricultural producer, food manufacturer, or pesticide manufacturer. 
Potentially affected entities may include, but are not limited to:
     Crop production (NAICS 111), e.g., agricultural workers; 
greenhouse, nursery, and floriculture workers; farmers.
     Animal production (NAICS 112), e.g., cattle ranchers and 
farmers, dairy cattle farmers, livestock farmers.
     Food manufacturing (NAICS 311), e.g., agricultural 
workers; farmers; greenhouse, nursery, and floriculture workers; 
ranchers; pesticide applicators.
     Pesticide manufacturing (NAICS 32532), e.g., agricultural 
workers; commercial applicators; farmers; greenhouse, nursery, and 
floriculture workers; residential users.
    This listing is not intended to be exhaustive, but rather provides 
a guide for readers regarding entities likely to be affected by this 
action. Other types of entities not listed in this unit could also be 
affected. The North American Industrial Classification System (NAICS) 
codes have been provided to assist you and others in determining 
whether this action might apply to certain entities. If you have any 
questions regarding the applicability of this action to a particular 
entity, consult the person listed under FOR FURTHER INFORMATION 
CONTACT.

B. How Can I Access Electronic Copies of This Document and Other 
Related Information?

    In addition to using EDOCKET (http://www.epa.gov/edocket/), you may 
access this Federal Register document electronically through the EPA 
Internet under the ``Federal Register'' listings at http://www.epa.gov/fedrgstr/. A frequently updated electronic version of 40 CFR part 180 
is available at E-CFR Beta Site Two at http://www.gpoaccess.gov/ecfr/. 
To access the OPPTS Harmonized Guidelines referenced in this document, 
go directly to the guidelines at http://www.epa.gpo/opptsfrs/home/guidelin.htm/.

II. Background and Statutory Findings

    In the Federal Register of July 7, 2004 (69 FR 40909) (FRL-7364-8), 
EPA issued a notice pursuant to section 408(d)(3) of FFDCA, 21 U.S.C. 
346a(d)(3), announcing the filing of a pesticide petition (PP 0F6135) 
by E.I. DuPont de Nemours and Company, DuPont Crop Protection, Barley 
Mill Plaza, Wilmington, DE 19880-0038. The petition requested that 40 
CFR 180.451 be amended by establishing a tolerance for residues of the 
herbicide tribenuron methyl, [methyl 2-[[[[(4-methoxy -6-methyl-1, 3, 
5-triazin-2-yl) methylamino] carbobyl]amino]sulfonyl]benzoate], in or 
on imazethapyr tolerant canola at 0.02 parts per million (ppm), cotton 
gin trash at 0.02 ppm, cotton seed at 0.02 ppm, and Crop Development 
Center (CDC) triffid flax at 0.02 ppm. That notice included a summary 
of the petition prepared by E. I. DuPont de Nemours and Company, the 
registrant. There were no comments received in response to the notice 
of filing.
    During the course of the review the Agency decided to correct the 
Company address and correct the listings for the commodities canola, 
cotton and flax. The company address is changed to DuPont Crop 
Protection, Stine-Haskell Research Center, Newark, DE 19714. The 
listing of the commodities imazethapyr tolerant canola, cotton seed, 
cotton gin trash and Crop Development Center (CDC) triffid flax are 
corrected to read canola, seed; cotton, undelinted seed; cotton, gin 
byproducts and flax, seed; respectively.
    Section 408(b)(2)(A)(i) of FFDCA allows EPA to establish a 
tolerance (the legal limit for a pesticide chemical residue in or on a 
food) only if EPA determines that the tolerance is ``safe.'' Section 
408(b)(2)(A)(ii) of FFDCA defines ``safe'' to mean that ``there is a 
reasonable certainty that no harm will result from aggregate exposure 
to the pesticide chemical residue, including all anticipated dietary 
exposures and all other exposures for which there is reliable 
information.'' This includes exposure through drinking water and in 
residential settings, but does not include occupational exposure. 
Section 408(b)(2)(C) of FFDCA requires EPA to give special 
consideration to exposure of infants and children to the pesticide 
chemical residue in establishing a tolerance and to ``ensure that there 
is a reasonable certainty that no harm will result to infants and 
children from aggregate exposure to the pesticide chemical residue. * * 
*''
    EPA performs a number of analyses to determine the risks from 
aggregate

[[Page 56712]]

exposure to pesticide residues. For further discussion of the 
regulatory requirements of section 408 of FFDCA and a complete 
description of the risk assessment process, see the final rule on 
Bifenthrin Pesticide Tolerances (62 FR 62961, November 26, 1997) (FRL-
5754-7).

III. Aggregate Risk Assessment and Determination of Safety

    Consistent with section 408(b)(2)(D) of FFDCA, EPA has reviewed the 
available scientific data and other relevant information in support of 
this action. EPA has sufficient data to assess the hazards of and to 
make a determination on aggregate exposure, consistent with section 
408(b)(2) of FFDCA, for a tolerance for residues of tribenuron methyl 
on canola, seed at 0.02 ppm, cotton, gin byproducts at 0.02 ppm, 
cotton, undelinted seed at 0.02 ppm, and flax, seed at 0.02 ppm. EPA's 
assessment of exposures and risks associated with establishing the 
tolerance follows.

A. Toxicological Profile

    EPA has evaluated the available toxicity data and considered its 
validity, completeness, and reliability as well as the relationship of 
the results of the studies to human risk. EPA has also considered 
available information concerning the variability of the sensitivities 
of major identifiable subgroups of consumers, including infants and 
children. The nature of the toxic effects caused by tribenuron methyl 
are discussed in Table 1 of this unit as well as the no-observed-
adverse-effect-level (NOAEL) and the lowest-observed-adverse-effect-
level (LOAEL) from the toxicity studies reviewed.

                                Table 1.--Subchronic, Chronic, and Other Toxicity
----------------------------------------------------------------------------------------------------------------
             Guideline No.                       Study Type                            Results
----------------------------------------------------------------------------------------------------------------
870.3100                                 90-Day oral toxicity--      NOAEL = 7 (males and 8 (females) milligrams/
                                          rodents                     kilogram/day (mg/kg/day)
                                                                     LOAEL = 118 (males) and 135 (females) mg/kg/
                                                                      day based on decreased body weight gain,
                                                                      food consumption and food efficiency;
                                                                      decreased absolute heart, liver, and
                                                                      kidney weights; increase relative brain,
                                                                      heart, liver, kidney, testes, and spleen
                                                                      weights; decreased serum glucose and
                                                                      globulin; no histopathologic lesions;
                                                                      likely cachexia
----------------------------------------
870.3150                                 90-Day oral toxicity--      NOAEL = > 73.3 (males) and > 78.0 (females)
                                          nonrodents                  HDT mg/kg/day
----------------------------------------
870.3200                                 21/28-Day dermal toxicity   NOAEL = limit dose, 1,000 mg/kg/day,
                                                                      resulted in serious toxicity and death. No
                                                                      NOAEL or LOEAL defined. Toxicity included
                                                                      treatment site lesions, hypokinesia,
                                                                      decreased body weights and food
                                                                      consumption, and kidney pathology, but the
                                                                      cause of death could not be determined.
                                                                      Although this study is core supplementary,
                                                                      another study is not needed. Worker
                                                                      exposure is expected to be 4 to 5 orders
                                                                      of magnitude less than limit dose.
----------------------------------------
870.3700                                 Prenatal developmental--    Maternal NOAEL = 20 mg/kg/day
                                          rodents                    Maternal LOAEL = 125 mg/kg/day based on
                                                                      decreased maternal body weight gain and
                                                                      food consumption
                                                                     Developmental NOAEL = 20 mg/kg/day
                                                                     Developmental LOAEL = 125 mg/kg/day based
                                                                      on decreased body weight. At 500 mg/kg/day
                                                                      (HDT) there were increased resorption,
                                                                      fetal deaths, and incomplete ossifications
----------------------------------------
870.3700                                 Prenatal developmental--    Maternal NOAEL = 20 mg/kg/day
                                          nonrodents                 Maternal LOAEL = 80 (HDT) mg/kg/day based
                                                                      on 10% decreased food consumption,
                                                                      increased abortions
                                                                     Developmental NOAEL = 20 mg/kg/day
                                                                     Developmental LOAEL = 80 mg/kg/day based on
                                                                      HDT-10% decrease in body weight compared
                                                                      to controls-not statistically
                                                                      significant). Abortions were increased at
                                                                      80 mg/kg/day. Teratology was not observed.
----------------------------------------
870.3800                                 Reproduction and fertility  Parental/Systemic NOAEL = 2 mg/kg/day
                                          effects                    Parental/Systemic LOAEL = 21 mg/kg/day
                                                                      based on decreased body weight gain in F1a
                                                                      adult females
                                                                     Reproductive NOAEL = 2.5 mg/kg/day
                                                                     Reproductive LOAEL = 25 mg/kg/day based on
                                                                      decreased body weight gain during
                                                                      lactation for F1b and F2b pups
                                                                     Offspring NOAEL = 2.5 mg/kg/day
                                                                     Offspring LOAEL = 25 mg/kg/day based on
                                                                      decreased absolute splenic weights
----------------------------------------
870.4100                                 Chronic toxicity--rodents   NOAEL = 0.95 (males)/1.2 (females) mg/kg/
                                                                      day
                                                                     LOAEL = 10 (males)/13 (females) mg/kg/day
                                                                      based on decreased body weight gain in
                                                                      both sexes.
                                                                     Statistically significant increase in
                                                                      mammary gland adenocarcinomas in female
                                                                      rats at 76 mg/kg/day highest dose tested
                                                                      (HDT)
----------------------------------------
870.4100                                 Chronic toxicity--dogs      NOAEL = 0.79 (males)/8.16 (females) mg/kg/
                                                                      day
                                                                     LOAEL = 8.18 (males)/52.02 (females) mg/kg/
                                                                      day based on elevated serum bilirubin,
                                                                      AST, and urinary volume, reduced body
                                                                      weight gain (20%) in females; increased
                                                                      serum creatinine, bilirubin, AST, and
                                                                      globulin, decreased body weight gain of
                                                                      18.2% in males.
----------------------------------------

[[Page 56713]]

 
870.4200                                 Carcinogenicity--rats       NOAEL = 0.95 (males)/1.2 (females) mg/kg/
                                                                      day
                                                                     LOAEL = 10 (males)/13 (females) mg/kg/day
                                                                      based on decreased body weight gain in
                                                                      both sexes.
                                                                     Statistically significant increase in
                                                                      mammary gland adenocarcinomas in female
                                                                      rats at 76 mg/kg/day (HDT)
----------------------------------------
870.4300                                 Supplement-Estrogenic       Dose levels: 0 and 390 mg/kg/day for 90
                                          Activity in Rats            days.
                                                                     Weak estrogenic activity was observed in
                                                                      female rats. The technical and seven
                                                                      metabolites may be agonists for the
                                                                      estrogen receptor.
----------------------------------------
870.4300                                 Carcinogenicity--mice       NOAEL = 3 (males) mg/kg/day
                                                                     LOAEL = 30 mg/kg/day based on bilateral
                                                                      seminiferous degenertion and oligospermia.
                                                                      Although frank toxicity was not observed
                                                                      in the females, HED peer review judged the
                                                                      dose levels to be adequate.
                                                                     No evidence of carcinogenicity
----------------------------------------
870.5100                                 Gene mutation Bacterial     negative in Salmonella Typhimurium
----------------------------------------
870.5300                                 Gene Mutation Mammalian     negative in Chinese hamster ovary cells in
                                                                      in vitro
----------------------------------------
870.5375                                 Cytogenetics                negative for structural chromosomal damage
                                                                      and when tested in a micronucleus test in
                                                                      mice
----------------------------------------
870.7485                                 Metabolism and              The major route of excretion in rats is the
                                          pharmacokinetics            urine. Urine samples contained two to four
                                                                      times of the administered radioactivity
                                                                      than the feces. Tissue levels of
                                                                      tribenuron methyl and its metabolites
                                                                      increased with dose, but there was no
                                                                      concentration of radioactivity in any
                                                                      particular organ or tissue.
----------------------------------------------------------------------------------------------------------------

B. Toxicological Endpoints

    The dose at which no adverse effects are observed (the NOAEL) from 
the toxicology study identified as appropriate for use in risk 
assessment is used to estimate the toxicological level of concern 
(LOC). However, the lowest dose at which adverse effects of concern are 
identified (the LOAEL) is sometimes used for risk assessment if no 
NOAEL was achieved in the toxicology study selected. An uncertainty 
factor (UF) is applied to reflect uncertainties inherent in the 
extrapolation from laboratory animal data to humans and in the 
variations in sensitivity among members of the human population as well 
as other unknowns. An UF of 100 is routinely used, 10X to account for 
interspecies differences and 10X for intraspecies differences.
    Three other types of safety or uncertainty factors may be used: 
``Traditional uncertainty factors;'' the ``special FQPA safety 
factor;'' and the ``default FQPA safety factor.'' By the term 
``traditional uncertainty factor,'' EPA is referring to those 
additional uncertainty factors used prior to FQPA passage to account 
for database deficiencies. These traditional uncertainty factors have 
been incorporated by the FQPA into the additional safety factor for the 
protection of infants and children. The term ``special FQPA safety 
factor'' refers to those safety factors that are deemed necessary for 
the protection of infants and children primarily as a result of the 
FQPA. The ``default FQPA safety factor'' is the additional 10X safety 
factor that is mandated by the statute unless it is decided that there 
are reliable data to choose a different additional factor (potentially 
a traditional uncertainty factor or a special FQPA safety factor).
    For dietary risk assessment (other than cancer) the Agency uses the 
UF to calculate an acute or chronic reference dose (aRfD or cRfD) where 
the RfD is equal to the NOAEL divided by an UF of 100 to account for 
interspecies and intraspecies differences and any traditional 
uncertainty factors deemed appropriate (RfD = NOAEL/UF). Where a 
special FQPA safety factor or the default FQPA safety factor is used, 
this additional factor is applied to the RfD by dividing the RfD by 
such additional factor. The acute or chronic Population Adjusted Dose 
(aPAD or cPAD) is a modification of the RfD to accommodate this type of 
safety factor.
    For non-dietary risk assessments (other than cancer) the UF is used 
to determine the LOC. For example, when 100 is the appropriate UF (10X 
to account for interspecies differences and 10X for intraspecies 
differences) the LOC is 100. To estimate risk, a ratio of the NOAEL to 
exposures (margin of exposure (MOE) = NOAEL/exposure) is calculated and 
compared to the LOC.
    The linear default risk methodology (Q*) is the primary method 
currently used by the Agency to quantify carcinogenic risk. The Q* 
approach assumes that any amount of exposure will lead to some degree 
of cancer risk. A Q* is calculated and used to estimate risk which 
represents a probability of occurrence of additional cancer cases 
(e.g., risk). An example of how such a probability risk is expressed 
would be to describe the risk as one in one hundred thousand (1 X 
10-\5\), one in a million (1 X 10-\6\), or 1 in 
10 million (1 X 10-\7\). Under certain specific 
circumstances, MOE calculations will be used for the carcinogenic risk 
assessment. In this non-linear approach, a ``point of departure'' is 
identified below which carcinogenic effects are not expected. The point 
of departure is typically a NOAEL based on an endpoint related to 
cancer effects though it may be a different value derived from the dose 
response curve. To estimate risk, a ratio of the point of departure to 
exposure (MOEcancer = point of departure/exposures) is 
calculated.
    A summary of the toxicological endpoints for tribenuron methyl used 
for human risk assessment is shown in the following Table 2:

[[Page 56714]]



  Table 2.--Summary of Toxicological Dose and Endpoints for Tribenuron methyl for Use in Human Risk Assessment
----------------------------------------------------------------------------------------------------------------
                                          Dose Used in Risk
                                             Assessment,          Special FQPA SF and
          Exposure Scenario                Interspecies and       Level of Concern for   Study and Toxicological
                                         Intraspecies and any       Risk Assessment              Effects
                                            Traditional UF
----------------------------------------------------------------------------------------------------------------
Chronic Dietary (All populations)      NOAEL= 0.8 mg/kg/day     Special FQPA SF = 1      Chronic Dog LOAEL = 8.2
                                       UF = 100...............  cPAD = chronic RfD /      mg/kg/day based on
                                       Chronic RfD = 0.008 mg/   Special FQPA SF =        elevated bilirubin,
                                        kg/day.                  0.008 mg/kg/day.         elevated serum liver
                                                                                          enzymes, increased
                                                                                          urinary volume, and
                                                                                          20% reduction in body
                                                                                          weight gain.
--------------------------------------
Cancer (oral, dermal, inhalation)      Classified as Group C    chronic risk assessment  NA
                                        (possible human          protective of any
                                        carcinogen) not          potential carcinogenic
                                        mutagenic)               risk
----------------------------------------------------------------------------------------------------------------

C. Exposure Assessment

    1. Dietary exposure from food and feed uses. Tolerances have been 
established (40 CFR 180.451) for the residues of tribenuron methyl, in 
or on a variety of raw agricultural commodities. Tolerances are 
established for barley, oats, wheat, and grass forage and hay group. No 
tolerances for meat products, eggs, or milk are established. Risk 
assessments were conducted by EPA to assess dietary exposures from 
tribenuron methyl in food as follows:
    i. Acute exposure. Acute dietary risk assessments are performed for 
a food-use pesticide, if a toxicological study has indicated the 
possibility of an effect of concern occurring as a result of a 1-day or 
single exposure.
    There are no studies that identify an acute hazard based on toxic 
effects observed following a single oral exposure (dose) of tribenuron 
methyl. The developmental toxicity rat study in which a 9% reduction in 
body weight occurred on the fourth day of dosing (day 9) was 
considered. However, this reduction in body weight gain was only slight 
and could not be attributed to a single dose since the reduction 
occurred on day 4 of dosing. Other effects observed in the 
developmental toxicity study such as decreased fetal wight (7.4%) and 
increased incidence of fetal resorptions (not statistically 
significant) were considered for an endpoint in reproductive females, 
but again, effects could not be attributed to a single dose. Since 
there was no litter loss or other acute effects, the aRfD is not 
appropriate for the assessment.
    ii. Chronic exposure. Dietary exposure estimates were conducted 
using the Lifeline model (Version 2.0) which incorporates consumption 
data from the USDA Continuing Surveys of Food Intakes by Individuals 
(CSFII), 1994-96 and 1998. The 1994-96, 1998 data are based on reported 
consumption of more than 20,000 individuals over two non-consecutive 
survey days. Foods ``as consumed'' are linked to EPA-defined food 
commodities using publicly available recipe translation files 
(developed jointly by USDA/ARS and EPA). Lifeline models individual 
dietary exposures over a season by selecting a new CSFII diary each day 
from a set of similar individuals, based on age and season attributes. 
The Lifeline chronic dietary exposure estimate is based on an average 
daily exposure from a profile of 1,000 individuals over a 1-year 
period. Further information regarding the Lifetime model can be found 
at the following we site:www.Lifeline TMgroup.org.
    The following assumptions were made for the chronic exposure 
assessments: Tolerance level, 100% crop treated (CT), and default 
processing factors were used. Percent crop treated (PCT) or anticipated 
residues were not used.
    iii. Cancer. Tribenuron methyl is classified as a Group C (Possible 
Human Carcinogen). The Agency also concluded that the carcinogenic 
response observed may be associated with a hormonal imbalance that may 
not occur at doses below a maximum tolerated dose ( MTD). A 
quantitative carcinogenic risk assessment for tribenuron methyl is not 
considered appropriate because: (1) The increased incidence of mammary 
gland tumors was observed in female rats treated at the dose levels 
exceeding the (MTD; (2) there was no evidence of genetic toxicity shown 
in several studies; (3) structural analogs of tribenuron methyl were 
not associated with carcinogenic responses in rats and mice. In 
conclusion the Agency considers the chronic risk assessment, making use 
of the cPAD, to be protective of any potential carcinogenic risk.
    2. Dietary exposure from drinking water. The Agency lacks 
sufficient monitoring exposure data to complete a comprehensive dietary 
exposure analysis and risk assessment for tribenuron methyl in drinking 
water. Because the Agency does not have comprehensive monitoring data, 
drinking water concentration estimates are made by reliance on 
simulation or modeling taking into account data on the physical 
characteristics of tribenuron methyl.
    The Agency uses the FQPA Index Reservoir Screening Tool (FIRST) or 
the Pesticide Root Zone Model/Exposure Analysis Modeling System (PRZM/
EXAMS), to produce estimates of pesticide concentrations in an index 
reservoir. The SCI-GROW model is used to predict pesticide 
concentrations in shallow ground water. For a screening-level 
assessment for surface water EPA will use FIRST (a tier 1 model) before 
using PRZM/EXAMS (a tier 2 model). The FIRST model is a subset of the 
PRZM/EXAMS model that uses a specific high-end runoff scenario for 
pesticides. Both FIRST and PRZM/EXAMS incorporate an index reservoir 
environment, and both models include a percent crop area factor as an 
adjustment to account for the maximum percent crop coverage within a 
watershed or drainage basin.
    None of these models include consideration of the impact processing 
(mixing, dilution, or treatment) of raw water for distribution as 
drinking water would likely have on the removal of pesticides from the 
source water. The primary use of these models by the Agency at this 
stage is to provide a screen for sorting out pesticides for which it is 
unlikely that drinking water concentrations would exceed human health 
levels of concern.
    Since the models used are considered to be screening tools in the 
risk assessment process, the Agency does not use estimated 
environmental concentrations (EECs), which are the model estimates of a 
pesticide's concentration in water. EECs derived from these models are 
used to quantify drinking water exposure and risk as a %RfD or %PAD. 
Instead, drinking water levels of comparison (DWLOCs) are

[[Page 56715]]

calculated and used as a point of comparison against the model 
estimates of a pesticide's concentration in water. DWLOCs are 
theoretical upper limits on a pesticide's concentration in drinking 
water in light of total aggregate exposure to a pesticide in food, and 
from residential uses. Since DWLOCs address total aggregate exposure to 
tribenuron methyl they are further discussed in the aggregate risk Unit 
III.E.
    Based on the FIRST, and SCI-GROW models, the EECs of tribenuron 
methyl for chronic exposures are estimated to be .413 ppb for surface 
water and 0.000006 ppb for ground water.
    3. From non-dietary exposure. The term ``residential exposure'' is 
used in this document to refer to non-occupational, non-dietary 
exposure (e.g., for lawn and garden pest control, indoor pest control, 
termiticides, and flea and tick control on pets).
    Tribenuron methyl is not registered for use on any sites that would 
result in residential exposure.
    4. Cumulative effects from substances with a common mechanism of 
toxicity. Section 408(b)(2)(D)(v) of FFDCA requires that, when 
considering whether to establish, modify, or revoke a tolerance, the 
Agency consider ``available information'' concerning the cumulative 
effects of a particular pesticide's residues and ``other substances 
that have a common mechanism of toxicity.''
    Unlike other pesticides for which EPA has followed a cumulative 
risk approach based on a common mechanism of toxicity, EPA has not made 
a common mechanism of toxicity finding as to tribenuron methyl and any 
other substances and tribenuron methyl does not appear to produce a 
toxic metabolite produced by other substances. For the purposes of this 
tolerance action, therefore, EPA has not assumed that tribenuron methyl 
has a common mechanism of toxicity with other substances. For 
information regarding EPA's efforts to determine which chemicals have a 
common mechanism of toxicity and to evaluate the cumulative effects of 
such chemicals, see the policy statements released by EPA's Office of 
Pesticide Programs (OPP) concerning common mechanism determinations and 
procedures for cumulating effects from substances found to have a 
common mechanism on EPA's web site at http://www.epa.gov/pesticides/cumulative/.

D. Safety Factor for Infants and Children

    1. In general. Section 408 of FFDCA provides that EPA shall apply 
an additional 10-fold margin of safety for infants and children in the 
case of threshold effects to account for prenatal and postnatal 
toxicity and the completeness of the database on toxicity and exposure 
unless EPA determines based on reliable data that a different margin of 
safety will be safe for infants and children. Margins of safety are 
incorporated into EPA risk assessments either directly through use of a 
maragin of exposure (MOE) analysis or through using uncertainty 
(safety) factors in calculating a dose level that poses no appreciable 
risk to humans. In applying this provision, EPA either retains the 
default value of 10X when reliable data do not support the choice of a 
different factor, or, if reliable data are available, EPA uses a 
different additional safety factor value based on the use of 
traditional uncertainty factors and/or special FQPA safety factors, as 
appropriate.
    2. Prenatal and postnatal sensitivity. Developmental and 
reproductive toxicity studies indicated no increased susceptibility of 
offspring to tribenuron methyl. However, increased number of 
resorptions (not statistically significant) and fetal deaths were 
observed at the highest dose tested when administered during the 
critical gestation period of pregnancy, in both the rat and the rabbit. 
The resorptions and fetal deaths indicate an effect due to maternal 
toxicity. In a two-generation reproduction study, reproductive effects 
of tribenuron methyl were limited to decreased body weight gain during 
lactation.
    3. Conclusion. There is a complete toxicity database for tribenuron 
methyl and exposure data are complete or are estimated based on data 
that reasonably accounts for potential exposures. The impact of 
tribenuron methyl on the nervous system has not been specifically 
evaluated in neurotoxicity studies. However, there was no evidence of 
neurotoxicity or neuropathology seen in either acute, subchronic, 
chronic, or reproductive studies, and there are no concerns for 
potential developmental neurotoxicity. Therefore, neurotoxicity data 
are not required for tribenuron methyl. EPA determined that the 10X SF 
to protect infants and children should be removed. The FQPA factor is 
removed because of the completeness of the toxicity and exposure 
database and because the available data provided no indication of 
increased susceptibility (quantitative or qualitative) to rats or 
rabbits following in utero exposure to tribenuron methyl, or to 
prenatal and/or postnatal exposure in rat reproduction studies and 
there are no concerns for potential developmental neurotoxicity.

E. Aggregate Risks and Determination of Safety

    To estimate total aggregate exposure to a pesticide from food, 
drinking water, and residential uses, the Agency calculates DWLOCs 
(drinking water level of concern) which are used as a point of 
comparison against EECs. DWLOC values are not regulatory standards for 
drinking water. DWLOCs are theoretical upper limits on a pesticide's 
concentration in drinking water in light of total aggregate exposure to 
a pesticide in food and residential uses. In calculating a DWLOC, the 
Agency determines how much of the acceptable exposure (i.e., the PAD) 
is available for exposure through drinking water e.g., allowable 
chronic water exposure (mg/kg/day) = cPAD - (average food + residential 
exposure). This allowable exposure through drinking water is used to 
calculate a DWLOC.
    A DWLOC will vary depending on the toxic endpoint, drinking water 
consumption, and body weights. Default body weights and consumption 
values as used by the EPA's Office of Water are used to calculate 
DWLOCs: 2 liter (L)/70 kg (adult male), 2L/60 kg (adult female), and 
1L/10 kg (child). Default body weights and drinking water consumption 
values vary on an individual basis. This variation will be taken into 
account in more refined screening-level and quantitative drinking water 
exposure assessments. Different populations will have different DWLOCs. 
Generally, a DWLOC is calculated for each type of risk assessment used: 
Acute, short-term, intermediate-term, chronic, and cancer.
    When EECs for surface water and ground water are less than the 
calculated DWLOCs, OPP concludes with reasonable certainty that 
exposures to the pesticide in drinking water (when considered along 
with other sources of exposure for which OPP has reliable data) would 
not result in unacceptable levels of aggregate human health risk at 
this time. Because OPP considers the aggregate risk resulting from 
multiple exposure pathways associated with a pesticide's uses, levels 
of comparison in drinking water may vary as those uses change. If new 
uses are added in the future, OPP will reassess the potential impacts 
of residues of the pesticide in drinking water as a part of the 
aggregate risk assessment process.
    1. Acute risk. An acute risk assessment was not performed; there 
were no studies that identify an acute hazard based on toxic effects 
observed following a single oral exposure (dose) of tribenuron methyl.

[[Page 56716]]

    2. Chronic risk. Using the exposure assumptions described in this 
unit for chronic exposure, EPA has concluded that exposure to 
tribenuron methyl from food will utilize <1% of the cPAD for the U.S. 
population, <1% of the cPAD for all infants <1 year old, and <1% of the 
cPAD for children 3 to 5 years old. There are no residential uses for 
tribenuron methyl that result in chronic residential exposure to 
tribenuron methyl. In addition, there is potential for chronic dietary 
exposure to tribenuron methyl in drinking water. After calculating 
DWLOCs and comparing them to the EECs for surface and ground water, EPA 
does not expect the aggregate exposure to exceed 100% of the cPAD, as 
shown in the following Table 3:

           Table 3.--Aggregate Risk Assessment for Chronic (Non-Cancer) Exposure to Tribenuron Methyl
----------------------------------------------------------------------------------------------------------------
                                                                             Surface       Ground
              Population Subgroup                cPAD mg/kg/     % cPAD     Water EEC    Water EEC     Chronic
                                                     day         (Food)       (ppb)        (ppb)     DWLOC (ppb)
----------------------------------------------------------------------------------------------------------------
U. S. Population                                       0.008           <1         .413      .000006          300
------------------------------------------------
All infants < 1 year old                               0.008           <1         .413      .000006          100
------------------------------------------------
Children 1-2 years old                                 0.008           <1         .413      .000006          100
------------------------------------------------
Children 3-5 years old                                 0.008           <1         .413      .000006          100
------------------------------------------------
Females 13-49 years old                                0.008           <1         .413      .000006          200
----------------------------------------------------------------------------------------------------------------

    3. Short-term risk. Short-term aggregate exposure takes into 
account residential exposure plus chronic exposure to food and water 
(considered to be a background exposure level).
    Tribenuron methyl is not registered for use on any sites that would 
result in residential exposure. Therefore, the aggregate risk is the 
sum of the risk from food and water, which do not exceed the Agency's 
level of concern.
    4. Intermediate-term risk. Intermediate-term aggregate exposure 
takes into account residential exposure plus chronic exposure to food 
and water (considered to be a background exposure level).
    Tribenuron methyl is not registered for use on any sites that would 
result in residential exposure. Therefore, the aggregate risk is the 
sum of the risk from food and water, which do not exceed the Agency's 
level of concern.
    5. Aggregate cancer risk for U.S. population. The Agency considers 
the chronic aggregate risk assessment, making use of the cPAD, to be 
protective of any aggregate cancer risk. See Table 3, Unit III.E.2. 
Therefore, the aggregate risk is not expected to exceed the Agency`s 
level of concern.
    6. Determination of safety. Based on these risk assessments, EPA 
concludes that there is a reasonable certainty that no harm will result 
to the general population, and to infants and children from aggregate 
exposure to tribenuron methyl residues.

IV. Other Considerations

A. Analytical Enforcement Methodology

    Adequate analytical methodology including liquid chromatography 
with a photoconductivity detector; high-performance liquid 
chromatography with UV detection (HPLC/UV); and gas chromatography 
using mass spectral detection (GC/MS) are available for enforcement of 
reassessed tolerances. These methods are published in PAM II.
    Adequate enforcement methodology --liquid chromatography with 
detection via electospray mass spectroscopy is available to enforce the 
tolerance expression for canola, flax, and cotton. The method may be 
requested from: Chief, Analytical Chemistry Branch, Environmental 
Science Center, 701 Mapes Rd., Ft. Meade, MD 20755-5350; telephone 
number: (410) 305-2905; e-mail address: [email protected].

B. International Residue Limits

    The maximum residue level (MRL) in Canada for tribenuron methyl on 
canola is 0.1 ppm. Available residue data and use pattern support a 
U.S. tolerance of 0.02 ppm. No Mexican or Codex MRLs exist for 
tribenuron methyl on canola. There are no Canadian, Mexican, or Codex 
MRLs for tribenuron methyl on cotton or flax.

C. Conditions

    Based on the tolerance reassessment for barley, oats, and wheat, 
residue data are required for barley, hay; oat forage and hay; and 
wheat forage and hay. Submission of this data and proposal of 
appropriate tolerances will be required. There are no conditions of 
registration for the establishment of tolerances on canola, cotton, or 
flax.

V. Conclusion

    Therefore, the tolerance is established for residues of tibenuron 
methyl, methyl 2-[[[[(4-methoxy-6-methyl-1, 3, 5-triazin-2-yl) 
methylamino]carbobyl]amino] sulfonyl]benzoate, in or on canola, seed at 
0.02 ppm; cotton, gin byproducts at 0.02 ppm; cotton, undelinted seed 
at 0.02 ppm, and flax, seed at 0.02 ppm. This action results in the 
reassessment of 8 tolerances as follows: barley, grain at 0.05 ppm; 
barley, straw at 0.10 ppm; oat, grain at 0.05 ppm; oat, straw at 0.1 
ppm; wheat, grain at 0.05 ppm; wheat, straw at 0.10 ppm; and tolerances 
with regional registration for grass, forage, fodder, and hay group 
(except bermudagrass); forage at 0.10 ppm; and grass, forage, fodder, 
and hay group (except bermudagrass); hay at 0.10 ppm listed in 40 CFR 
180.451. Also, even though many of the tolerancs for the current 
commodities listed in Sec.  180.451 have not been changed and only 
tolerances for canola, seed; cotton, gin byproducts; cotton, undelinted 
seed; and flax, seed are being added, EPA is printing Sec.  180.451 in 
its entirety to restructure the section so that it matched the other 
sections in subpart C.

VI. Objections and Hearing Requests

    Under section 408(g) of FFDCA, as amended by FQPA, any person may 
file an objection to any aspect of this regulation and may also request 
a hearing on those objections. The EPA procedural regulations which 
govern the submission of objections and requests for hearings appear in 
40 CFR part 178. Although the procedures in those regulations require 
some modification to reflect the amendments made to FFDCA by FQPA, EPA 
will continue to use those procedures, with appropriate adjustments, 
until the necessary modifications can be made. The new section 408(g) 
of FFDCA provides essentially the same process for persons to 
``object'' to a regulation for an exemption from the requirement of a

[[Page 56717]]

tolerance issued by EPA under new section 408(d) of FFDCA, as was 
provided in the old sections 408 and 409 of FFDCA. However, the period 
for filing objections is now 60 days, rather than 30 days.

A. What Do I Need to Do To File an Objection or Request a Hearing?

    You must file your objection or request a hearing on this 
regulation in accordance with the instructions provided in this unit 
and in 40 CFR part 178. To ensure proper receipt by EPA, you must 
identify docket ID number OPP-2004-0278. in the subject line on the 
first page of your submission. All requests must be in writing, and 
must be mailed or delivered to the Hearing Clerk on or before November 
22, 2004.
    1. Filing the request. Your objection must specify the specific 
provisions in the regulation that you object to, and the grounds for 
the objections (40 CFR 178.25). If a hearing is requested, the 
objections must include a statement of the factual issues(s) on which a 
hearing is requested, the requestor's contentions on such issues, and a 
summary of any evidence relied upon by the objector (40 CFR 178.27). 
Information submitted in connection with an objection or hearing 
request may be claimed confidential by marking any part or all of that 
information as CBI. Information so marked will not be disclosed except 
in accordance with procedures set forth in 40 CFR part 2. A copy of the 
information that does not contain CBI must be submitted for inclusion 
in the public record. Information not marked confidential may be 
disclosed publicly by EPA without prior notice.
    Mail your written request to: Office of the Hearing Clerk (1900L), 
Environmental Protection Agency, 1200 Pennsylvania Ave., NW., 
Washington, DC 20460-0001. You may also deliver your request to the 
Office of the Hearing Clerk in Suite 350, 1099 14th St., NW., 
Washington, DC 20005. The Office of the Hearing Clerk is open from 8 
a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The 
telephone number for the Office of the Hearing Clerk is (202) 564-6255.
    2. Copies for the Docket. In addition to filing an objection or 
hearing request with the Hearing Clerk as described in Unit VI.A., you 
should also send a copy of your request to the PIRIB for its inclusion 
in the official record that is described in ADDRESSES. Mail your 
copies, identified by docket ID number OPP-2004-0278, to: Public 
Information and Records Integrity Branch, Information Resources and 
Services Division (7502C), Office of Pesticide Programs, Environmental 
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-
0001. In person or by courier, bring a copy to the location of the 
PIRIB described in ADDRESSES. You may also send an electronic copy of 
your request via e-mail to: [email protected]. Please use an ASCII 
file format and avoid the use of special characters and any form of 
encryption. Copies of electronic objections and hearing requests will 
also be accepted on disks in WordPerfect 6.1/8.0 or ASCII file format. 
Do not include any CBI in your electronic copy. You may also submit an 
electronic copy of your request at many Federal Depository Libraries.

B. When Will the Agency Grant a Request for a Hearing?

    A request for a hearing will be granted if the Administrator 
determines that the material submitted shows the following: There is a 
genuine and substantial issue of fact; there is a reasonable 
possibility that available evidence identified by the requestor would, 
if established resolve one or more of such issues in favor of the 
requestor, taking into account uncontested claims or facts to the 
contrary; and resolution of the factual issues(s) in the manner sought 
by the requestor would be adequate to justify the action requested (40 
CFR 178.32).

VII. Statutory and Executive Order Reviews

    This final rule establishes a tolerance under section 408(d) of 
FFDCA in response to a petition submitted to the Agency. The Office of 
Management and Budget (OMB) has exempted these types of actions from 
review under Executive Order 12866, entitled Regulatory Planning and 
Review (58 FR 51735, October 4, 1993). Because this rule has been 
exempted from review under Executive Order 12866 due to its lack of 
significance, this rule is not subject to Executive Order 13211, 
Actions Concerning Regulations That Significantly Affect Energy Supply, 
Distribution, or Use (66 FR 28355, May 22, 2001). This final rule does 
not contain any information collections subject to OMB approval under 
the Paperwork Reduction Act (PRA), 44 U.S.C. 3501 et seq., or impose 
any enforceable duty or contain any unfunded mandate as described under 
Title II of the Unfunded Mandates Reform Act of 1995 (UMRA) (Public Law 
104-4). Nor does it require any special considerations under Executive 
Order 12898, entitled Federal Actions to Address Environmental Justice 
in Minority Populations and Low-Income Populations (59 FR 7629, 
February 16, 1994); or OMB review or any Agency action under Executive 
Order 13045, entitled Protection of Children from Environmental Health 
Risks and Safety Risks (62 FR 19885, April 23, 1997). This action does 
not involve any technical standards that would require Agency 
consideration of voluntary consensus standards pursuant to section 
12(d) of the National Technology Transfer and Advancement Act of 1995 
(NTTAA), Public Law 104-113, section 12(d) (15 U.S.C. 272 note). Since 
tolerances and exemptions that are established on the basis of a 
petition under section 408(d) of FFDCA, such as the tolerance in this 
final rule, do not require the issuance of a proposed rule, the 
requirements of the Regulatory Flexibility Act (RFA) (5 U.S.C. 601 et 
seq.), do not apply. In addition, the Agency has determined that this 
action will not have a substantial direct effect on States, on the 
relationship between the national government and the States, or on the 
distribution of power and responsibilities among the various levels of 
government, as specified in Executive Order 13132, entitled Federalism 
(64 FR 43255, August 10, 1999). Executive Order 13132 requires EPA to 
develop an accountable process to ensure ``meaningful and timely input 
by State and local officials in the development of regulatory policies 
that have federalism implications.'' ``Policies that have federalism 
implications'' is defined in the Executive order to include regulations 
that have ``substantial direct effects on the States, on the 
relationship between the national government and the States, or on the 
distribution of power and responsibilities among the various levels of 
government.'' This final rule directly regulates growers, food 
processors, food handlers and food retailers, not States. This action 
does not alter the relationships or distribution of power and 
responsibilities established by Congress in the preemption provisions 
of section 408(n)(4) of FFDCA. For these same reasons, the Agency has 
determined that this rule does not have any ``tribal implications'' as 
described in Executive Order 13175, entitled Consultation and 
Coordination with Indian Tribal Governments (65 FR 67249, November 6, 
2000). Executive Order 13175, requires EPA to develop an accountable 
process to ensure ``meaningful and timely input by tribal officials in 
the development of regulatory policies that have tribal implications.'' 
``Policies that have tribal implications'' is defined in the Executive 
order to include regulations that have ``substantial direct effects on 
one or more Indian tribes, on the

[[Page 56718]]

relationship between the Federal Government and the Indian tribes, or 
on the distribution of power and responsibilities between the Federal 
Government and Indian tribes.'' This rule will not have substantial 
direct effects on tribal governments, on the relationship between the 
Federal Government and Indian tribes, or on the distribution of power 
and responsibilities between the Federal Government and Indian tribes, 
as specified in Executive Order 13175. Thus, Executive Order 13175 does 
not apply to this rule.

VIII. Congressional Review Act

    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the 
Small Business Regulatory Enforcement Fairness Act of 1996, generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report, which includes a copy of the rule, 
to each House of the Congress and to the Comptroller General of the 
United States. EPA will submit a report containing this rule and other 
required information to the U.S. Senate, the U.S. House of 
Representatives, and the Comptroller General of the United States prior 
to publication of this final rule in the Federal Register. This final 
rule is not a ``major rule'' as defined by 5 U.S.C. 804(2).

List of Subjects in 40 CFR Part 180

    Environmental protection, Administrative practice and procedure, 
Agricultural commodities, Pesticides and pests, Reporting and 
recordkeeping requirements.

    Dated: September 10, 2004.
Lois Rossi,
Director, Registration Division, Office of Pesticide Programs.

0
Therefore, 40 CFR chapter I is amended as follows:

PART 180--AMENDED

0
1. The authority citation for part 180 continues to read as follows:

    Authority: 21 U.S.C. 321(q), 346a and 371.

0
2. Section 180.451 is revised to read as follows:


Sec.  180.451  Tribenuron methyl; tolerances for residues.

    (a) General. Tolerances are established for the residues of the 
herbicide tribenuron methyl (methyl-2-[[[[N-(4-methoxy-6-methyl-1,3,5-
triazin-2-yl) methylamino] carbonyl]amino]sulfonyl] benzoate) in or on 
the following raw agricultural commodities:

------------------------------------------------------------------------
                                                              Parts per
                         Commodity                             million
------------------------------------------------------------------------
Barley, grain..............................................         0.05
Barley, straw..............................................         0.10
Canola, seed...............................................         0.02
Cotton, gin byproducts.....................................         0.02
Cotton, undelinted seed....................................         0.02
Flax, seed.................................................         0.02
Oat, grain.................................................         0.05
Oat, straw.................................................         0.10
Wheat, grain...............................................         0.05
Wheat, straw...............................................         0.10
------------------------------------------------------------------------

    (b) Section 18 emergency exemptions. [Reserved]
    (c) Tolerances with regional registrations. Tolerances with 
regional registration, as defined in Sec.  180.1(n) are established for 
residues of the herbicide tribenuron methyl (methyl-2-[[[[N-(4-methoxy-
6-methyl-1,3,5-triazin-2-yl) methylamino] carbonyl]amino]sulfonyl] 
benzoate) in or on the following raw agricultural commodities:

------------------------------------------------------------------------
                                                              Parts per
                         Commodity                             million
------------------------------------------------------------------------
Grass, forage, fodder and hay, group (except Bermudagrass);         0.10
 forage....................................................
Grass, forage, fodder and hay, group (except Bermudagrass);         0.10
 hay.......................................................
------------------------------------------------------------------------

    (d) Indirect or inadvertent residues. [Reserved]
[FR Doc. 04-20982 Filed 9-21-04; 8:45 am]
BILLING CODE 6560-50-S